Frangible Fastener Socket Assembly With Retained Section Ejection

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Solution Overview

Problem

Current manual tools for installing frangible fasteners lack an efficient method for disposing of the fractured portion, which can be hazardous and inconvenient, and existing automated systems are costly and require frequent recalibration.

Innovation Solution

A tooling assembly with a socket body and pin that allows reversible rotation, featuring a frictional retaining element to hold the severable section of the frangible fastener during installation and subsequent ejection for disposal, utilizing a driving mechanism to torque and fracture the fastener, then translate the pin to expel the severed section from the socket body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If manual tooling is used to install frangible fasteners, then cost is reduced and maintenance is minimized, but disposal of the fractured portion becomes hazardous and inconvenient

Engineering Contradiction:
Improvetooling costVSAvoiddisposal convenience
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent combines the installation function and disposal function into a single integrated tooling assembly. The socket body retains the fractured portion during installation, then the pin mechanism ejects it for disposal, merging two separate operations into one tool without requiring automated systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The tooling assembly performs disposal automatically through the pin ejection mechanism that is activated during the installation process itself. The fractured portion is ejected by the pin translating in the bore, allowing the tool to service its own disposal function without external automation.

Inventive Principle:
Principle #25Self-service

2Productivity

If automated tooling is used to install frangible fasteners, then installation efficiency is improved, but cost increases and recalibration is required frequently

Engineering Contradiction:
Improveinstallation efficiencyVSAvoidtooling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The socket body serves multiple functions: it engages the frangible fastener during installation, retains the fractured portion after fracture, and works with the pin mechanism for ejection. This multi-functionality eliminates the need for separate retention and ejection mechanisms, reducing complexity while maintaining automation benefits.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The pin acts as an intermediary mechanism between the driving mechanism and the fractured portion. It translates rotational motion during installation into linear motion for ejection, mediating between the two functions without requiring complex automated disposal systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the socket body is designed with threads for pin engagement, then the pin can be translated to eject the fractured portion, but the socket body structure becomes more complex

Engineering Contradiction:
Improveejection capabilityVSAvoidsocket body structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The bore is segmented into different functional zones: a first end portion for pin reception, a central portion with threads for engagement, and a second end portion for fractured portion retention. This segmentation allows each zone to perform its specific function while keeping the overall structure integrated and manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The same threaded central portion of the bore serves dual purposes: during installation, the threads engage the pin to prevent its rotation while allowing translation; during ejection, the threads again engage the pin but now translate rotational motion into ejection force. The structure is inverted in function but not in form, reducing complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables efficient and safe installation of frangible fasteners with automated disposal of the severed section, reducing maintenance costs and improving operational efficiency compared to traditional methods.

Implementation Method 1

A frangible fastener is inserted in a socket in a second end portion of a bore in the socket body and engaged by a frictional retaining element

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The driving mechanism rotates the socket body in a first direction torqueing the frangible fastener on the stud fracturing the severable section

Methodology Applied
Scientific EffectTorque: Torque

Implementation Method 3

mating threads on the pin engage threads in a central portion of the bore to translate the pin urging the severable section out of contact with the frictional retaining element and ejecting the severable section from the second end portion

Methodology Applied
Scientific EffectThreaded engagement: Screw

Data Source

PatentEP3479962B1Tooling assembly and method for installation of a frangible fastener
Publication Date: 2021.08.04 THE BOEING CO
  • EP3479962B1 patent drawingFigure 1
  • EP3479962B1 patent drawingFigure 2
  • EP3479962B1 patent drawingFigure 3

AI summary

A tooling assembly (10) for fastener installation has a socket body (22) reversibly rotatable by a driving mechanism (12). A bore (26) in the socket body has a first end portion (30) and a central portion (32) incorporating threads (34). A second end portion (36) of the bore receives and engages a severable section (42) of a frangible fastener (14). A pin (50) is received in the bore and constrained from rotation by the driving mechanism. The pin has an ejection shaft (56) with mating threads (58) selectively receivable in the threads of the central portion of the bore. The socket body is freely rotatable with the mating threads positioned in the first end portion of the bore. Rotation of the socket body in torques the frangible fastener on a stud (16) fracturing the severable section. Reverse rotation of the socket body engages the mating threads in the threads translating the pin. The ejection shaft ejects the severable section from the second end portion.